Amplitude-Dependent Damping in Vibration Serviceability: Case of a Laboratory Footbridge

AbstractConstruction technology advancements in the last couple of decades have led to the use of lightweight and high-strength materials in structural systems. Although longer spans and lighter materials result in floor systems with less mass, stiffness, and damping, the trend toward a paperless office decreases damping and the amount of live load on the floors even more. Consequently, structures have become more vulnerable to annoying vibrations, and vibration serviceability has become an area of serviceability concern. For vibration serviceability calculations, the damping value of the structural systems is a critical parameter. Damping in structures has proved to be dependent on the amplitude of the applied force on the structure. This condition is referred to as nonlinear damping, or amplitude-dependent damping. Although damping is constant at low and high amplitudes, for in-between amplitudes, the damping value increases with the levels of excitation amplitude. For wind and earthquake excitations, t...